流动注射-化学发光法测定盐酸洛美沙星

在酸性条件下盐酸洛美沙星可与Ce(Ⅳ)产生化学发光反应，罗丹明6G对该反应有较强的增敏作用。据此，建立了流动注射-化学发光法测定盐酸洛美沙星的新方法。该方法的线性范围为0．10～15．0mg／L，检出限为0．06mg／L，相对标准偏差(n=11，c=1．00mg／L)为1．2％，回收率为95％～102％。本法用于胶囊中盐酸洛美沙星含量的测定，分析结果满意。     

鲁米诺-过硫酸钠化学发光体系测定硝苯地平

过硫酸钠在碱性条件下能氧化鲁米诺产生微弱化学发光,硝苯地平能大大增强此发光。基于此．建立起了一种直接测定硝苯地平的流动注射化学发光方法。该方法线性范围为0．05～5．0mg／L;检出限为0．017mg/L;相对标准偏差为2．8％(硝苯地平0．5mg／L,n=11)。利用该方法测定了硝苯地平片剂含量,结果令人满意。     

流动注射化学发光法测定异烟肼

基于在氢氧化钠碱性介质中高锰酸钾氧化异烟肼的化学发光现象,提出高锰酸钾．异烟肼．氢氧化钠化学发光新体系,结合流动注射分析技术进行了异烟肼的测定。本法选择性好、灵敏度高。异烟肼在0．01～5．0mg/L浓度范围内与化学发光分析信号呈线性关系;检出限为7．0μg／L;对0．5mg/L的异烟肼进行11次连续测定,相对标准偏差为2．5％。方法已成功地应用于片剂中异烟肼的测定。     

葡萄糖的流动注射化学发光法测定

葡萄糖在浓盐酸中降解后,其产物羟甲糖醛可与Ce(Ⅵ）反应产生化学发光,罗丹明6G对该反应有较强的增敏作用。据此,建立了流动注射化学发光测定葡萄糖的新方法。该法的线性范围为0．2－90mg/L,检出限为0．08mg/L,相对标准偏差(n=11,ρ=10.0mg/L）为1．0％。方法用于血清中葡萄糖含量的测定,结果与标准方法一致,回收率为96％－106％。     

鲁米诺-高锰酸钾-苯酚化学发光体系研究

基于鲁米诺-高锰酸钾-苯酚体系很好的化学发光特性,建立一种测定苯酚的流动注射化学发光分析新方法。在最优化实验条件下,苯酚浓度在0．001—2．5mg／L范围内与化学发光强度呈良好的线性关系,标准曲线为ΔI=750．45C(mg／L) 1．4655(n=8,r^2=0．9998),检出限(3σ)为0．35μg/L;对0．05和0．5mg／L的苯酚进行11次平行测定,相对标准偏差(RSD)分别为0．6％和2．5％。应用本法于合成样品和工业废水中苯酚的测定,结果令人满意。     

头孢曲松钠的流动注射化学发光抑制法测定

基于吖啶橙在氢氧化钠介质中，能被高锰酸钾氧化产生较强的化学发光，头孢曲松钠能强烈抑制其化学发光，建立了高锰酸钾-吖啶橙-头孢曲松钠化学发光抑制测定头孢曲松钠的方法；头孢曲松钠的质量浓度与化学发光强度在2～20mg／L范围内呈良好线性关系，方法的检出限为8μg/L，对10mg／L头孢曲松钠连续进行11次测定的相对标准偏差为3．1％；方法用于头孢曲松钠针剂测定，取得了满意的结果。     

流动注射化学发光法测定尼莫地平

利用尼莫地平对ce（Ⅳ)-Na2SO3化学发光体系的抑制作用,建立了流动注射—化学发光法测定尼莫地平的新方法。化学发光强度与尼莫地平浓度在0．5～90mg/L范围内呈线性关系,线性范围为0．5～10mg/L时,r=0．9990;线性范围为10～90mg/L时,r=0．9968。回收率在98．3％～103．2％范围内;检出限为0．085mg/L。     

阿昔洛韦-过氧化氢-钴(Ⅱ)化学发光体系的研究和应用

在碱性介质中,Co^2 催化H2O2氧化阿昔洛韦产生强的化学发光。基于此,结合流动注射技术,建立了阿昔洛韦的化学发光测定新方法。该方法简单、快捷,测定阿昔洛韦的线性范围为0．8—60mg／L;检出限为0．2mg／L(3σ);对0．8mg／L的阿昔洛韦进行11次测定,计算出方法的相对标准偏差为6．3％。将此方法用于片剂中阿昔洛韦含量的测定,结果令人满意。     

阻抑速差催化光度法测定痕量色氨酸和酪氨酸

研究了色氨酸、酪氨酸在硫酸环境中抑制碘对亚砷酸与硫酸铈氧化还原反应的催化作用及动力学条件。在0．001mol／L Ce(SO4)2,0．00125mol／L As2O3,0．013mg／L KI,0．025g／L和0．25g／L NaCl溶液中测定色氨酸和酪氨酸,其线性范围分别为0．0～0．65mg／L,0．0～4．0mg／L和0．0～1．3mg／L。0．10～4．0mg／L,用联立方程分别求出各自含量。用此法对醇溶蛋白质和混合氨基酸溶液中色氨酸和酪氨酸进行测定,混合氨基酸的色氨酸、酪氨酸测量值为0．8037g／L,3．591g/L;蛋白质的色氨酸、酪氨酸测量值为1．8g/kg、3．43g/kg;回收率在88％～109％;色氨酸和酪氨酸的RSD分别为4．8％和5．2％,结果满意。     

核壳纳米晶二硒化镉/硫化镉的合成及荧光法测定溶菌酶

以3-巯基丙酸为修饰剂,水相合成了具有发光效率高,光稳定性强等优良特性的CdSe2／CdS核壳纳米晶,粒径约为4nm,并将其成功用于溶菌酶的测定。在pH7．4的Na2HPO4-NaH2PO4缓冲溶液中,以365nm激发,体系在642nm处的荧光强度与溶菌酶的浓度呈线性关系,线性响应范围为0．5～8．0mg／L和8.0～32mg／L;线性方程分别为△F=0．97 2．21C(mg/L)和△F=12．20 0．70C(mg／L);检出限为0．20mg／L。将该方法应用于样品的测定,结果令人满意。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.